Linkages between grazing history and herbivore exclusion on decomposition rates in mineral soils of subalpine grasslands
Linkages between grazing history and herbivore exclusion on decomposition rates in mineral soils of subalpine grasslands
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DOI：
10.1007/s11104-013-1905-8
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发表时间：
2014-01-01
期刊：
影响因子：
4.9
通讯作者：
Risch, Anita C.
中科院分区：
文献类型：
--
作者：
Haynes, Alan G.;Schuetz, Martin;Risch, Anita C.
草食动物驱动的土壤性质变化可以影响草地生态系统中有机物质的分解速率，从而影响土壤碳循环。研究了在不同放牧历史的两种亚高山植被类型（矮草和高草）中，地上觅食哺乳动物和无脊椎食草动物对矿质土壤分解速率和相关土壤性质的影响。使用不同网孔大小的封闭物，我们逐步将大型、中型和小型哺乳动物和无脊椎动物从瑞士国家公园（SNP）的两种植被类型中排除。2010年5 - 9月，采用棉布（标准基质）法评价了矿质土分解率。分解表现出强烈的时空变异性，最好的解释是土壤温度。排除大型哺乳动物增加了分解率，但进一步排除又降低了轻度放牧（高草）植被的分解率。在重度放牧（短草）植被上，不同处理间无差异。由于土壤温度较高，重度放牧区分解速率高于轻度放牧区。微生物生物量碳和土壤碳氮比也与时空分解模式有关，但与放牧历史无关。尽管改变了分解的一些环境控制，但SNP亚高山草原的纤维素分解率似乎主要抵抗短期食草动物的排斥。
Herbivore-driven changes to soil properties can influence the decomposition rate of organic material and therefore soil carbon cycling within grassland ecosystems. We investigated how aboveground foraging mammalian and invertebrate herbivores affect mineral soil decomposition rates and associated soil properties in two subalpine vegetation types (short-grass and tall-grass) with different grazing histories.Using exclosures with differing mesh sizes, we progressively excluded large, medium and small mammals and invertebrates from the two vegetation types in the Swiss National Park (SNP). Mineral soil decomposition rates were assessed using the cotton cloth (standard substrate) method between May and September 2010.Decomposition displayed strong spatio-temporal variability, best explained by soil temperature. Exclusion of large mammals increased decomposition rates, but further exclusion reduced decomposition rates again in the lightly grazed (tall-grass) vegetation. No difference among treatments was found in the heavily grazed (short-grass) vegetation. Heavily grazed areas had higher decomposition rates than the lightly grazed areas because of higher soil temperatures. Microbial biomass carbon and soil C:N ratio were also linked to spatio-temporal decomposition patterns, but not to grazing history.Despite altering some of the environmental controls of decomposition, cellulose decomposition rates in the SNP's subalpine grasslands appear to be mostly resistant to short-term herbivore exclusion.